Segregation Requirements

Attachment 18 covers compatibility of shipping hazardous materials together on the same air transport. The general requirements state that packages containing hazardous materials that might react dangerously with one another must not be loaded or transported in a way that would allow the materials to interact with each other in case of leakage.

Segregation requirements for hazardous materials transported on military aircraft are listed in Tables A18.2 and A18.3. A18.2 details segregation requirements for all hazardous materials, while A18.3 specifies compatibility requirements for Class 1 explosives.

A18.4 specifies compatibility requirements for tactical and contingency operations under the authority of Chapter 3.

Table A18.1 indicates hazardous materials that must not be loaded, transported, or stored together. Only the primary class and division hazard is considered for segregations. Subsidiary hazards and secondary hazards do not need to be considered when using Table A18.1

In A18.1, the absence of a hazard class, or a blank space, indicates that no restrictions apply. An "X" at the intersection of horizontal and vertical columns indicate that these articles must not be loaded, transported, or stored together (example Class 3 Flammable Liquids must not be loaded, transported, or stored with Class 1.1).

An "O" at the intersection of horizontal and vertical columns indicates that these articles must not be loaded, transported, or stored together unless separated by a distance of 2.2 meters (88 inches) in all directions, or one 463L pallet position.

A * (asterisk) at the intersection of horizontal and vertical columns indicates that segregation among different Class 1 materials is identified in Table A18.2.

Make sure to check any notes for compatibility issues, as well.

Table A18.2 identifies Class 1 Explosives that must not be loaded, transported, or stored together.

A blank space indicates that no restrictions apply, while an "X" at the intersection of horizontal and vertical columns indicates that these articles must not be loaded or stored together.

Unless otherwise authorized, do not pack explosives in the same outside container with other articles. Explosives from the same compatibility group, or authorized combination of compatibility groups but a different class number may be packed together; however, the whole package must be treated as though its entire contents were comprised of the lower class number (and thus higher hazard).

Subsidiary hazards do not need to be considered when using Table A18.2.

Make sure to check any notes for compatibility issues, as well.

Refer to A18.3 for more details and examples of Class 1 segregation requirements.

A18.4 details that the segregation and compatibility requirements of Table A18.1 and A18.2 may be deviated from when transporting cargo approved for airlift under Chapter 3 provisions.

Normally incompatible materials may be transported on the same aircraft when separated to the maximum extent possible. Compatibility waivers are not required.

Refer to A18.4.1 through A18.4.5 for mandatory restrictions.

Table A18.3 describes the classification codes and compatibility groups of explosives. The classification code consists of the Class number, 1, followed by the compatibility group letter.

Compatibility group letters specify the required controls for transportation and storage, to prevent the additional hazard that could occur if certain types of explosives are transported or stored together.

All explosives entering the Defense Transportation System must be assigned a final or interim hazard classification according to A3.3.1.4. Table A18.3 lists the compatibility groups and classification codes for various types of substances and articles.

To learn more about Shipping HAZMAT visit our Shipping HAZMAT By Military Aircraft Online Training web page.